1. Field of the Invention
The present invention relates to a radio communication system which manages entry of a mobile terminal into a predetermined area.
2. Description of the Related Art
There is available a technique for detecting a mobile terminal's entering a predetermined area or a mobile terminal's exiting the predetermined area using radio communication. This technique is expected to be applied to various fields. For example, road pricing assumes that when a vehicle enters a toll area, the vehicle is charged a predetermined fare. However, implementation of the road pricing requires installation of an apparatus for detecting entry of a vehicle on every road through which a vehicle can enter a toll area and suffers from time or cost problems.
As a countermeasure against this, Japanese Patent Laid-Open No. 2003-30701 discloses a technique for determining the position of a vehicle on which a mobile terminal is mounted using a base station apparatus of a mobile communication system and sensing, from the position, whether the vehicle has entered a toll area. The technique eliminates the need to install an entry detection apparatus on every road.
However, in order to detect every vehicle entering a toll area by the technique disclosed in Japanese Patent Laid-Open No. 2003-30701, regardless of channel through which the vehicle enters the toll area, it is necessary to enable all base station apparatuses within the toll area to detect entry of a mobile terminal instead of installing an entry detection apparatus on every road. For this reason, all the base station apparatuses within the toll area need to support road pricing.